Improvement in machines for sharpening harvester-knives



J. S, ELLIOTT.

Machines for sharpening Harvester-Knives. No. 138,743, I Ptente dMay13,1873..

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AM. PHOTU-UTHOGIMPIIIC ca .wqmsanus mapesq) UNITED STATES PATENT QEEICE.

'J-OSIAH s. ELLIOTT, OF CHELSEA, MASSACHUSETTS.

IMPROVEMENT m MACHINES FOR SHARPENING HARVESTER-KNIVES.

Specification forming part of Letters Patent No. 138,743, dated May 13,1873; application filed December 13, 1872.

To all whom it may concern.-

Be it known that I, J osmn S. ELLIOTT, of Chelsea, in the State of Massachusetts, have invented an Improvement in Machines for -Sharpening the Blades of Hay-Cutters, Harvesters, 850.; and I do hereby declare the following to be a full and correct description of the same, reference being had to the accompanying drawing, in which- Figure 1 is a side elevation. Fig.2 is a front elevation. Fig. 3 is a sectional elevation, showing the holding device and its ,relation to the emery-wheel. Fig. 4 is a plan. Figs. 5, 6, 7, and 8 are views of portions of the holding mechanism in detail.

A is the frame. B is an emery-wheel, mounted upon an arbor having bearings in movable blocks a a, which have a motion up and down in slots in the frame, their movement being governed by set-screws b b, as shown. The

object of this movement is to allow differentsized wheels to be used in one frame or machine, or to allow a wheel to be lowered as it wears away, so that it may continue to do its work properly. In the drawing, the wheel is shown with a flat rim. In the machine the rim is beveled both ways from the center. The emery-wheel is revolved by a pulley, 0, upon its arbor, whose belt passes around a large wheel, 0, driven by a crank and treadle, as shown. The belt is kept at proper tension by a peculiar belt-tightener, consisting of a bent weighted lever, D, pivoted upon the frame, as shown, and having upon the light arm a pin, upon which, as an axis, revolve two wheels on a double pulley, d, the belt passing over both wheels, as shown. The belt-tightener in addition to its proper office holds the belt out of the way of the carriage, whose movements are hereinafter to be described. E is the plat form, upon which the toothed knife or sawblade is presented to the emery-wheel. The knife is secured to the platform by a cam, Z, which presses the back or flange of the knife against the shoulder in the platform, the cam being secured to the platform behind the shoulder by a screw, as shown. The platform turns to the right or left upon a slide, shown in detail in Figs. 6 and 7, which moves backward and forward upon a guide-plate, n, shown in detail in Fig. 8. The slide 0 has projections upon its lower side embracing the edges of the guide-plate a, to keep the slide in place. The guide-plate n is secured to a table near the top and front of the frame, and forming a part thereof, by set-screws w and z. The screw 00 is the pivot upon which the guide-plate swings, and should be directly under the center of the emery-wheel, and equally distant from each side of the guide-plate. As new wheels from time to time are mounted upon the arbor, it may be necessary to move the screwm. This movement is obtained, as shown in Fig. 3, by a slot in the table, through which, the screw passes, while it also passes through a plate which is secured to the table bya screw, y, passing through a slot in the plate. The platform E is secured to the slide 0, as shown in Fig. 3, by two rings, (see Figs; 5 and 6,) the ring upon the slide fitting within the ring upon the platform. This connection allows to the platform its circular movement to the right or left,to permit the instrument which is to be sharpened to be presented to the emery-wheel with its back parallel to the arbor, whether the platform is moved forward from the right-hand corner of the machine or from the left-hand corner. The platform is locked in its proper position relatively to the slide by a screw, 10, which moves a plate, 1), which forms a section of the ring before referred to, as shown in Fig. 5. G is a swinging arm, hinged, as shown in Figs. 2 and 4, to a small plate, which is secured to the table of the frame, as shown, by a slot and set-screw, so as to have a horizontal movement in any direction. The swinging arms assist in sup porting the blade to be sharpened. But one arm is shown in the drawing, although two are used. The pin to which the second arm is attached is shown upon the opposite side of the machine in Figs. 2 and 4..

The operation is as follows: In order to sharpen the right-hand edge of one of the sawteeth, the knife is secured by its flange or shoulder to the platform E, as previously stated, by the cam l, and the guide-plate n is then moved to the left, until the opposite edge of the tooth is parallel to the guide-plate, and there fastened by the screw 2, the platform E being in the meantime so held that the shoulder or flange of the knife or blade is parallel with the arbor of the emery-wheel, in which position the platform is then secured upon the slide a by the screw w, as previously stated. The emery-Wheel is then put in motion, and the operator pushes forward the platform bearin g the knife, having always the work beneath his eye. This keeping the work in sight is one of the principal advantages of the invention. The right-hand edge of one tooth being thus properly sharpened, the cam l is turned back and the blade slipped along upon the platform and secured, so as, in the same manner, to grind the right-hand edge of the next tooth. After the right edge of each tooth has been sharpened, the guide-plate n is swung to the right, and the left edge of each tooth ground in like manner. p

scribed.

J. S. ELLIOTT. Witnesses:

WILLIAM W. SWAN, JOHN H. FIsHER. 

